This is at work. I have four threads of enquiry ongoing, one tab group for each. The nature of my work is that I have to do a good part of my research in the spaces between tasks.
Two of those threads/groups have become the same thread.
Normally I'll find what I'm looking for, but leave the tab up for awhile and let it simmer. Once a week or so I'll pare down a group to just the tabs that I'll want to refer to later, bookmark what remains and clear everything out.